#include <stdio.h>
     int main()
{    int n,x,y,z,k;
     scanf("%d%d%d",&n,&x,&y);
     if(k=y%x,k=0)
     z=n-y/x;
     else
     z=n-y/x-1;
     printf("%d\n",z);
     return 0;
}
